81540942 has 32 divisors (see below), whose sum is σ = 197344512. Its totient is φ = 21926784.

The previous prime is 81540937. The next prime is 81540947. The reversal of 81540942 is 24904518.

It is an interprime number because it is at equal distance from previous prime (81540937) and next prime (81540947).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81540947) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 56388 + ... + 57815.

It is an arithmetic number, because the mean of its divisors is an integer number (6167016).

Almost surely, 2^81540942 is an apocalyptic number.

81540942 is an abundant number, since it is smaller than the sum of its proper divisors (115803570).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81540942 is a wasteful number, since it uses less digits than its factorization.

81540942 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114232.

The product of its (nonzero) digits is 11520, while the sum is 33.

The square root of 81540942 is about 9030.0023255811. The cubic root of 81540942 is about 433.6359118813.

The spelling of 81540942 in words is "eighty-one million, five hundred forty thousand, nine hundred forty-two".